my mates jus bought a standard s2 which is overheating badly after only 5min of running he gave it good service and new thermostat but still the heating continues.dont think it is head gasket as no sludge in oil cap or oil in header tank so was thinking could be blockage or air lock somewhere............what would be best way and parts to check for these?? any advice greatly appreciated.thanks

 

I would feel the rad and pipes as it gets hot to see if they are blocked to start with.
If it's getting this hot in 5 minutes there is omething seriously wrong though.
tabetha

 

Could be a shagged waterpump, may just be heating the water in the head/block and nothing else......